三重交错Buck变换器的扰动观测器双闭环控制方法

The Dual Close Loop Control Method for the Disturbance Observer of Tri-interleaved Buck Converter

传统双闭环控制策略的三重交错Buck变换器,其暂态响应慢,并且输出电压的控制精度受输入电压波动、负载变化、滤波器参数变化等因素的影响。为了提高三重交错Buck变换器电压环的抗干扰性能和暂态响应速度,本文提出了基于扰动观测器和PI算法的双环控制策略。该策略将输入电压的波动、滤波器参数的变化和负载变化视为外部扰动,利用扰动观测器对其进行观测,将观测值前馈到电压环的输出端,抵消扰动对系统的影响。本文分析了观测器抑制扰动的机理,设计了扰动观测器,校正了电压环和电流环,仿真研究了变换器的暂态性能和抗扰性,研究结果表明所提出的控制策略提高了三重交错Buck变换器的抗干扰性能和暂态响应速度。

The transient response speed of the tri-interleaved buck converter that is controlled through a traditional double close loop control strategy is low. The filter’s parameters variation, loads variation and input voltage fluctuation have an effect on the output voltage’s control precision of the tri-interleaved buck converter. In order to improve transient response speed and disturbance rejection performance of the tri-interleaved buck converter’s voltage control loop, a control strategy based on disturbance observer(DOB) and PI algorithm is proposed for a tri-interleaved buck converter in this paper. The method regards filter’s parameters variation, loads variation and input voltage fluctuation as outside disturbance of the system,using a disturbance observer to observe these disturbances, and the observed values are forward fed to out terminal of voltage control loop to offset the effect of disturbance on the system. The rejecting disturbance mechanism of the DOB is theoretically analyzed. The DOB is designed, and then the current control loop and the voltage control loop are both compensated in this paper. Simulation experiments are done to compare the traditional double-loop control method and the proposed method, then the investigation results verify that the anti-disturbance performance and dynamic response speed of the tri-interleaved buck converter have been improved.